Reel drive mechanism for motionpicture projectors



J. J. KUEHN March zo, 1951 REEL DRIVE MECHANISM FOR MOTION-PICTUREPROJECTORS Filed nec. 7, 1945 s ,N\\ \\Nd 7 l /l y w Y 2 7 f a I. .olllhll. y 5 w.. 11H 5 m Y, J M ,HWI l1 n m Il n m u m., 6 WI. mm""` 2 yA. I` t v/H////V//////////////////,//f//////////////////////////////ffl/fila. Il.

JNVENTOR. JOHN J KUEHN Patented Mar. 20, 1951 REEL DRIVEMECHANISIWFORMOTION- PICTURE PROJ'ECTGRS John LKuehn, Chicago, Illg, assigner; bymesne assignmentato Illinois Watch Case Elgin, Ill., acorporationofllinois ApplicationDecember 7, 1945, Serial No. 633,297 ionen. (c1.afi- 3m i 'This invention relates to motionpicturelapparatus and moreparticularly to the nlmY reel driving mechanism of motionV pictureprojectors although not limited to thisuse alone.

In the conventional motion picture'machines or projectors the iilm is`positively` driven by the mechanism of the machine and is drawn from aroll onthefeed reel thereof` and wound upon a take-up reel whichisdriven by the mechanism 'of the machine by suitable yielding means,said means or mechanism accommodating for the slowing,v up ofithetake-upA reel as the iilm. roll hereo'n increases in diameter. Theconventional yielding take-upv driving mechanism provides a1substantially constantpower of the driven or 'take-up reel member withthe result that the take-uptension on the; lm'undesirably decreasesasthefdiameter oi the lm` roll on the take-up reel increases.

The primary object of the invention isk to provide means whereby thepower of the driven or-take-up reel member is automatically varied asthe diameter of the roll film on thetake-up reel increases withcorresponding decrease in speed'of the4 take-up reel.

Another object of the invention is to provide a film reel drivemechanism in which the fric- ,tional engagement between the drivingmeans and the driven means will automatically be varied depending uponthe tension of the film leaving thefeeding reel and tension of the nlmbeingwound upon the take-up or storing reel.

Still another object is to provide a mechanism in. which the. increasedfrictional engagement between the driving means and the drivenmeanswill' automatically be returned to a normal frictional engagement, whenthetension of. thelm isj changed. A further object is, to provideV ahousing to enclose the driving means and the driven means whereby aiiuid may be contained therein to keep the riotional surfaces of thediscs properly lubricated to permit the slip-friction desired When theload represented by the driven element is gradually or suddenly imposedon the driving element. l

A still further object of the invention is to provide a take-up drivemechanism which is more positive in its operation than a belt drivedepending upon the slip of said belt.

A still further object is to provide powerlil transmitting couplingspermitting the frictional n engagement of the driving and driven meansto vary, said couplings to be free of spring members or other tensiondevices which need adJustment from. time to time due to extensive usethereof.

Other and further objects. will be suggested toithose skilled in the artby the description which follows and nally embodied in the appendedclaim.

The invention will be better understood from the following descriptiontaken in connection with the accompanying drawings, in which:

Figure 1 is a side View of a projector which is constructed inaccordance with and which illustrates a preferred embodiment of theinvention, parts of the projector not being shown. g

Figure 2 is a sectional view of the arm. supporting the take-up reelshowing` the driving mechanism and friction couplings.

Figure 3Vis an enlarged sectional View of the. horsingenclosingA theyfrictiondiscsI as; shown in Figure 2.

inasmuch as: the invention relatesy particularly to themeans for drivingthe storing reelv for. the film, the accompanying drawings show only asmuch of the entire projector'as will be of assistance in apprehendingrthe invention.

Like characters of reference indicatel likeparts in the several views.

Referring to the'drawing, 5 designates the body of the machina. withbase ii, lens mount l, said body or housingV having supporting bracketsIl and lifor pivotally` supporting arms 8 and 9 for mounting reels forfilm lill as usual in a machine of this type.

Thefeeding reel is designated I4 and the takeup reel is designated i5.

Referring to Figure 2, the supporting bracket lf2 is formed with` a hubAl5 for housing a sleeve il, with bearing le arrangedtherein, tosupportadrivel shaft- Zii, which has asprocket gear 2l pinnedr thereto, and,vsaid shaft extending. horizontally into bearing 22. mounted in hubportion 25 of arm 9, said arm 9 being provided with a back plate 25 toenclose the arm and form a closed housing.

Secured on the arm 9 is a spring tensioned rod 2l, with button 28, saidrod assembled with spring 29, bearing 3D and pin 3l. The free end of rod2 ts into aperture 32 in bracket I2 to hold the arm 9 in the desiredposition during operation of the projector; however permitting pivotalmovement of the arm when the end thereof is withdrawn from aperture 32.

The opposite end of said arm 9 supports the driven shaft 35 supported bybearings 36 and 3l within said arm. Said shaft has a sprocket gear 38pinned thereon to receive the chain lill driven by gear 2| mounted onshaft 201 One end of the shaft 35 extends outside the arm 9 and has ametal cup shaped flange fil riveted, or otherwise, secured thereto, saidange having a horizontal, cylindrical portion 42, with externalscrewthreads 43 on its peripherial surface. Associated with cup shapedflange 4'2 is a cup shaped flange 45 with vertical wall 45 andcylindrical rim portion 4l, said rim portion 4l being provided on itsinterior with threads 48 for engagement with threads 43 of flange 42 toform an adjustable housing to enclose the yielding mechanism about to bedescribed and which was so greatly expounded in the aforesaid objects.

Enclosed between flanges il and i5 is a metallic disc 50 secured to theend of a film reel spindle by riveting or otherwise. Positioned betweensaid disc 55 and spindle 5I is secured a disc 52 forming a shoulder foruse with reel l5, said reel I5 being held in desired location upon thespindle 5l Vby means of spring tensioned ball 53, said parts forming anovel reel mount, Positioned on each side of said disc 55 is an assemblyof leather washers or disc-like friction members, 54 and 55. Thesefriction members are saturated with oil and held in close engagementwith ilanges :il and 45 as Well as disc 53 by adjusting the position or"flanges 52 and 4l. The disc' 50 may be of porous metal capable ofretaining oil or other liquids satisfactory for keeping the leather offiber discs 55 and 55 properly saturated. In the horizontal iiange il isarranged an oil gun fitting with tension ball valve, said valve topermit oil to be forced inside the housing formed by flanges il and l5when desired; as for example, once a year the leather discs should besuitably saturated. Said oil tting is designated on the drawing bynumeral 58.

The above described mechanism forms a yielding coupling permittingvariance of speed and power of the take-up reel spindle 5I dependentupon the instant diameter of the lm roll on a radially winding lm striptake-up reel driven by the reel spindle, said novel action beingaccomplished by the slippage of the leather discs 55 and 55 betweenmetal disc 50 and housings 4l and 45, said housings being locked inposition by set-screw 59 or some other suitable means. Further said disc59, being constructed of suitable metal and of desired weight has thecharacteristics of a floating flywheel which regulates the i frictionslip of said leather discs as well as the motion of the reel spindle andreel thereon. It is to be noted that the metal discs 55 and 52 securedto spindle 5l are not supported except by the clamping action of housingmembers il and 45; in other words members 55, 5| and 52 aresubstantially iioating. When the reel pull is increased, the force istransmitted to the weighted disc 55 which presses the friction rings 54and 55 4 into tighter engagement with said housings 4l and 45. As forexample, if the force is downward on spindle 5l, this force causes thelower portion of disc to press ring 55 against the lower part of wall4I; likewise, the upper portion of disc 50 presses ring 54 against thetop part of wall 46; this action increasing the friction and givesincreased power to drive the reel I5. Therefore, as the weight of thereel increases, the friction between the discs and the housingincreases, thus providing automatic compensation of power and frictionfor all sizes and weights of reels.

Although this invention has been described in considerable detail, suchdescription is intended to be illustrative rather than limiting aschanges may be readily made without departing from the spirit of theinvention, and the scope of the invention is to be determined asclaimed.

I claim as my invention:

A film reel drive mechanism of the character described, comprising: adrive shaft; a cupshaped driving disc mounted on said shaft for rotationtherewith; a second cup-shapedv driving disc mounted on said firstmentioned disc, the flange portions of each disc having complementarythreads for assembly of said discs into a housing of adjustable Width, adriven disc within said housing, said driven disc being rotatable aboutthe axis of rotation of said shaft and driving discs; annular members offrictional material on opposite sides of said driven disc frictionallycoupling said driven disc to said driving discs, said members offrictional material being saturated with a lubricant and said drivendisc being of porous metal capable of retaining a lubricant; and a reelspindle having one end mounted on said driven disc for rotation withsaid driven disc about said axis, said spindle extending through saidopening and being spaced from the walls of said opening to permitangular movement of the free end of said spindle to vary said frictionalcoupling as a function of the weight of a film spool on said spindle.

JOHN J. KUEHN.

REFERENCES CITED The following references are of record in the `nle ofthis patent:

UNITED STATES PATENTS Number Name Date 1,302,701 Parret May 6, 19191,365,732 Schmid et al. Jan. 18, 1921 1,920,967 Carpenter Aug. 8, 19332,005,096 Malickson June 18, 1935 2,083,646 Fuller June 15, 19372,461,033 Canady Feb. 8, 1949 2,472,983 Nemeth June 14, 1949

